Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
I have used mine in matches including taking 6th at the 2012 SH Cup with it as well as some top 5s but the recoil and larger cases aren't needed. It will not punch holes in steel even down to 100 yards but over all it's too much energy for the task at hand. Some people have shot them over the years but just moved to better options.
They make 10 round AI mags for the 300WM and have for some time. I used them in both my rifles but you are correct that they are long as they are single stack and not a staggered stack and single feed like the other AICS mags.
A brake or can is is definitely a huge help and highly recommended if you plan to shoot a 300 in matches. Will help you stay on target better.
As mentioned the 6.5 Creedmoor will do the job for both your needs. Unless you plan on taking the elk near 800 yards and out then the 300 would come in a little better with more energy. A friend of mine took a bull elk at 750 yards with his Creedmoor. No issues but shot placement is important.